Nuclear submarine

A nuclear submarine is a submarine powered by a nuclear reactor (see also Nuclear marine propulsion). The performance advantages of nuclear submarines over "conventional" (typically diesel-electric) submarines are considerable: nuclear propulsion, being completely independent of air, Sony VAIO PCG-3B1M Battery

frees the submarine from the need to surface frequently, as is necessary for conventional submarines; the large amount of power generated by a nuclear reactor allows nuclear submarines to operate at high speed for long durations; and the long interval between refuellings grants a range limited only by consumables such as food. Sony VAIO PCG-3C1T Battery

Current generations of nuclear submarines never need to be refueled throughout their 25-year lifespans.^[1] Conversely, the limited power stored in electric batteries means that even the most advanced conventional submarine can only remain submerged for a few days at slow speed, and only a few hours at top speed; Sony VAIO PCG-3D1M Battery

recent advances in air-independent propulsion have eroded this disadvantage somewhat. The high cost of nuclear technology means that relatively few states have fielded nuclear submarines. Some of the most serious nuclear and radiation accidents in the world have involved Soviet nuclear submarine mishaps. Sony VAIO PCG-3G2M Battery

The idea for a nuclear-powered submarine was first proposed by the Naval Research Laboratory's Ross Gunn^[4] in 1939.

The United States launched the USS Nautilus, the first nuclear submarine, in 1954.^[5] Nautilus could remain underwater for up to four months without resurfacing. Sony VAIO PCG-5R1M Battery

Construction of the Nautilus was made possible by the successful development of a nuclear propulsion plant by a group of scientists and engineers at the Naval Reactors Branch of the Atomic Energy Commission. In July 1951, the U.S. Congressauthorized construction of the world's first nuclear-powered submarine, under the leadership of Captain Hyman G. Rickover, USN.^[6] Sony VAIO PCG-7141M Battery

The Westinghouse Corporation was assigned to build its reactor. After the submarine was completed, Mamie Eisenhower broke the traditional bottle of champagne on Nautilus' bow. On 17 January 1955, it began its sea trials after leaving its dock in Groton, Connecticut. The submarine was 320 feet long, and cost about $55 million. Sony VAIO PCG-7143M Battery

The Soviet Union soon followed the United States in developing nuclear-powered submarines in the 1950s. Stimulated by the U.S. development of the Nautilus, Soviet work on nuclear propulsion reactors began in the early 1950s at the Institute of Physics and Power Engineering, in Obninsk, under Anatoliy P. Sony VAIO PCG-7151M Battery

Alexandrov, later to become head of the Kurchatov Institute. In 1956, the first Soviet propulsion reactor designed by his team began operational testing. Meanwhile, a design team under Vladimir N. Peregudov worked on the vessel that would house the reactor. Sony VAIO PCG-7154M Battery

After overcoming many obstacles, including steam generation problems, radiation leaks, and other difficulties, the first nuclear submarine based on these combined efforts entered service in the Soviet Navy in 1958.

At the height of the Cold War, Sony VAIO PCG-7162M Battery

approximately five to ten nuclear submarines were being commissioned from each of the four Soviet submarine yards (Sevmash in Severodvinsk, Admiralteyskiye Verfi in St. Petersburg, Krasnoye Sormovo in Nizhny Novgorod, and Amurskiy Zavod in Komsomolsk-on-Amur). Sony VAIO PCG-7181M Battery

From the late 1950s through the end of 1997, the Soviet Union, and later Russia, built a total of 245 nuclear submarines, more than all other nations combined.^[9]

Today, six countries deploy some form of nuclear-powered strategic submarines: the United States, Russia, France, the United Kingdom, People's Republic of China, and India.^[10Sony VAIO PCG-41112M Battery

^] Several other countries, including Argentina and Brazil,^[11][12] have ongoing projects in different phases to build nuclear-powered submarines.

In the United Kingdom, all former and current nuclear submarines for the Royal Navy (with the exception of three: Sony VAIO PCG-7153M Battery

HMSConqueror, HMS Renown and HMS Revenge) have been constructed in Barrow-in-Furness (at BAE Systems Submarine Solutions or its predecessor VSEL) where construction of nuclear submarines continues. Conqueror is the only nuclear-powered submarine ever to have engaged an enemy ship with torpedoes, Sony VAIO PCG-71312M Battery

sinking the cruiser ARA General Belgrano with two Mark 8 torpedoesduring the 1982 Falklands War.^{[note 1]}

Technology

The main difference between conventional submarines and nuclear submarines is the power generation system. Sony VAIO PCG-7144M Battery

Nuclear submarines employnuclear reactors for this task. They either generate electricity that powers electric motors connected to the propeller shaft or rely on the reactor heat to produce steam that drives steam turbines (cf. nuclear marine propulsion). Reactors used in submarines typically use highly enriched fuel Sony VAIO PCG-7191L Battery

(often greater than 20%) to enable them to deliver a large amount of power from a smaller reactor and operate longer between refuelings – which are difficult due to the reactor's position within the submarine's pressure hull.

The nuclear reactor also supplies power to the submarine's other subsystems, such as for maintenance of air quality, Sony VAIO PCG-3C1M Battery

fresh water production by distilling salt water from the ocean, temperature regulation, etc. All naval nuclear reactors currently in use are operated with diesel generators as a backup power system. These engines are able to provide emergency electrical power for reactordecay heat removal, as well as enough electric power to supply an emergency propulsion mechanism. Sony VAIO PCG-3F1M Battery

Submarines may carry nuclear fuel for up to 30 years of operation. The only resource that limits the time underwater is the food supply for the crew and maintenance of the vessel.

The stealth weakness of nuclear submarines is the need to cool the reactor even when the submarine is not moving; about 70% of the reactor output heat is coupled into the sea water. Sony VAIO PCG-3H1M Battery

This leaves a "thermal wake", a plume of warm water of lower density which ascends to the sea surface and creates a "thermal scar" observable by thermal imaging systems, e.g. FLIR.^[14] Another problem is that the reactor is always running, creating steam noise, which can be heard on SONAR, and the reactor pump (used to circulate reactor coolant), Sony VAIO PCG-3J1M Battery

also creates noise, as opposed to a conventional submarine, which can move about on incredibly silent electric motors.

USS Nautilus (SSN-571) is the world's first operational nuclear-powered submarine. She was the first vessel to complete a submerged transit beneath the North Pole on August 3, 1958. Sony VAIO PCG-8141M Battery

Namesake of the submarine in Jules Verne'sTwenty Thousand Leagues Under the Sea, and named after another USS Nautilus (SS-168) that served with distinction in WWII, Nautilus was authorized in 1951 and launched in 1954. Because her nuclear propulsion allowed her to remain submerged far longer than diesel-electric submarines, Sony VAIO PCG-8161M Battery

she broke many records in her first years of operation, and traveled to locations previously beyond the limits of submarines. In operation, she revealed a number of limitations in her design and construction. This information was used to improve subsequent submarines. Sony VAIO PCG-3C2M Battery

The Nautilus was decommissioned in 1980 and designated a National Historic Landmark in 1982. She has been preserved as a museum of submarine history in Groton, Connecticut, where she receives some 250,000 visitors a year.

Planning and construction

In July 1951 the United States Congress authorized the construction of a nuclear-powered submarine for the U.S. Sony VAIO PCG-5N2M Battery

Navy, which was planned and personally supervised by Admiral Hyman G. Rickover, known as the "Father of the Nuclear Navy."^[3] On 12 December 1951 the U.S. Department of the Navy announced that the submarine would be called Nautilus—the fourth U.S. Navy vessel officially so named^[4]—and would carry the hull number SSN-571. Sony VAIO PCG-5P1M Battery

Nautilus's keel was laid at General Dynamics' Electric Boat Division in Groton, Connecticutby Harry S. Truman, President of the United States, on 14 June 1952^[5], and the ship was designed by John Burnham. She was christened on 21 January 1954 and launched into the Thames River, sponsored by Mamie Eisenhower, Sony VAIO PCG-5S1M Battery

the wife of Truman's successor Dwight D. Eisenhower.Nautilus was commissioned on 30 September 1954, under the command of Commander Eugene P. Wilkinson, USN.

Nautilus was powered by the S2W naval reactor, a pressurized water reactor produced for the US Navy by Westinghouse Electric Corporation. Sony VAIO PCG-9Z1M Battery

Argonne National Laboratory, together with Westinghouse, developed the basic reactor plant design used in the USS Nautilus after being given the assignment on Dec. 31, 1947 to design a nuclear power plant for a submarine.^[6]Nuclear power had the crucial advantage in submarine propulsion because it is a zero-emission process that consumes no air. Sony VAIO PCG-7171M Battery

The physics-critical experiments supporting this design were performed at Argonne. This design is the basis for nearly all of the US nuclear-powered submarine and surface combat ships, and was adapted by other countries for naval nuclear propulsion. The first actual prototype (for the Nautilus) was constructed and tested by Argonne at the S1W facility in Idaho. Sony VAIO PCG-7186M Battery

"Underway on nuclear power"

Following her commissioning, Nautilus remained dockside for further construction and testing. At 11 a.m. on 17 January 1955 she put to sea for the first time and signaled her historic message: "Underway on nuclear power."^[7] Sony VAIO PCG-81112M Battery

On 10 May, she headed south for shakedown. Submerged throughout, she traveled 2,100 km (1,100 nautical miles) from New London to San Juan, Puerto Rico and covered 2,223 km (1,200 nm) in less than ninety hours. At the time this was the longest submerged cruise by a submarine and at the highest sustained speed (for at least one hour) ever recorded. Sony VAIO PCG-31311M Battery

From 1955 to 1957, Nautilus continued to be used to investigate the effects of increased submerged speeds and endurance. The improvements rendered the progress made in anti-submarine warfare during the Second World War virtually obsolete.Radar and anti-submarine aircraft, which had proved crucial in defeating submarines during the WarSony VAIO PCG-8152M Battery

proved ineffective against a vessel able to quickly move out of an area, change depth quickly and stay submerged for very long periods.

On 4 February 1957, Nautilus logged her 60,000th nautical mile (111,120 km), matching the endurance of her namesake, Sony VAIO VPC CW2MFX/PU Battery

the fictional Nautilus described in Jules Verne's novel Twenty Thousand Leagues Under The Sea.In May, she departed for the Pacific Coast to participate in coastal exercises and the fleet exercise, operation "Home Run," which acquainted units of the Pacific Fleet with the capabilities of nuclear submarines. Sony VAIO VPC S11V9E/B Battery

Nautilus returned to New London, Connecticut, on 21 July and departed again on 19 August for her first voyage of 2,226 km (1,202 nmi) under polar pack ice. Thereafter, she headed for the Eastern Atlantic to participate in NATO exercises and conduct a tour of various British and French ports where she was inspected by defense personnel of those countries. Sony VAIO VPCB119GJ/B Battery

She arrived back at New London on 28 October, underwent upkeep, and then conducted coastal operations until the spring.

Operation Sunshine - under the North Pole

In response to the nuclear ICBM threat posed by Sputnik, President Eisenhower ordered the US Navy to attempt a submarine transit of the North Pole to gain credibility for the soon-to-come SLBM weapons system.^[8] Sony VAIO VPCB11AGJ Battery

On 25 April 1958, Nautilus was underway again for the West Coast, now commanded by Commander William R. Anderson, USN. Stopping at San Diego, San Francisco, and Seattle, she began her history-making polar transit, operation "Sunshine", as she departed the latter port 9 June. Sony VAIO VPCB11AVJ Battery

On 19 June she entered the Chukchi Sea, but was turned back by deep draft ice in those shallow waters. On 28 June she arrived atPearl Harbor to await better ice conditions. By 23 July her wait was over, and she set a course northward. She submerged in the Barrow Sea Valley on 1 August and on 3 August, Sony VAIO VPCB11V9E Battery

at 2315 (EDST) she became the first watercraft to reach the geographicNorth Pole.^[9] The ability to navigate at extreme latitudes and without surfacing was enabled by the technology of the North American Aviation N6A-1 Inertial Navigation System, a naval modification of the N6A used in the Navaho cruise missile. Sony VAIO VPCB11X9E Battery

(The N6A-1 had been installed on the Nautilus and the Skate, after initial sea trials on the USS Compass Island in 1957.)^[10] From the North Pole, she continued on and after 96 hours and 1,590 nmi (2,940 km) under the ice, she surfaced northeast ofGreenland, having completed the first successful submerged voyage around the North Pole. Sony VAIO VPCCW18FJ/P Battery

The technical details of this mission were planned by scientists from the Naval Electronics Laboratory including Dr. Waldo Lyon who accompanied Nautilus as chief scientist and ice pilot.

Navigation beneath the arctic ice sheet was difficult. Above 85°N both magnetic compasses and normal gyrocompasses become inaccurate. Sony VAIO VPCCW18FJ/R Battery

A special gyrocompass built by Sperry Rand was installed shortly before the journey. There was a risk that the submarine would become disoriented beneath the ice and that the crew would have to play "longitude roulette". Commander Anderson had considered using torpedoes to blow a hole in the ice if the submarine needed to surface. Sony VAIO VPCCW18FJ/W Battery

As mentioned above, the most difficult part of the journey was in the Bering Strait. The ice extended as much as 60 feet (18 m) below sea level. During the initial attempt to go through the Bering Strait, there was insufficient room between the ice and the sea bottom. Sony VAIO VPCCW19FJ/W Battery

During the second, successful attempt to pass through the Bering passage, the submarine passed through a known channel close to Alaska (this was not the first choice as the submarine wanted to avoid detection).

The trip beneath the ice cap was an important boost to America as the Soviets had recently launched Sputnik, Sony VAIO VPCCW1AFJ Battery

but had no nuclear submarine of their own. During the address announcing the journey the president mentioned that one day nuclear cargo submarines might use that route for trade.

Proceeding from Greenland to the Isle of Portland, England, she received the Presidential Unit Citation, Sony VAIO VPCCW1AHJ Battery

the first ever issued in peace time, from American Ambassador J.H. Whitney, and then set a westerly course which put her into the Thames River estuary at New London 29 October. Captain Anderson would also be awarded the Legion of Merit by Eisenhower.^[8] For the remainder of the year Nautilus operated from her home port, New London, Connecticut. Sony VAIO VPCCW1S1E Battery

Operational history

Following fleet exercises in early 1959, Nautilus entered the Portsmouth Naval Shipyard in Kittery, Maine, for her first complete overhaul (28 May 1959 – 15 August 1960). Overhaul was followed by refresher training and on 24 October she departed New London for her first deployment with the Sixth Fleet in the Mediterranean Sea, returning to her home-port 16 December. Sony VAIO VPCCW1S1E/B Battery

Nautilus operated in the Atlantic, conducting evaluation tests for ASW improvements, participating in NATO exercises and, during October 1962, in the naval quarantine of Cuba, until she headed east again for a two month Mediterranean tour in August 1963. On her return she joined in fleet exercises until entering the Portsmouth Naval Shipyard for her second overhaul 17 January 1964. Sony VAIO VPCCW1S1E/L Battery

On 2 May 1966, Nautilus returned to her home-port to resume operations with the Atlantic Fleet, and at some point around that month, logged her 300,000th mile (560,000 km) underway. For the next year and a quarter she conducted special operations for ComSubLant and then in August 1967, returned to Portsmouth, Sony VAIO VPCCW1S1E/P Battery

for another year's stay, following which she conducted exercises off the southeastern seaboard. She returned to New London in December 1968.

In the spring^[when?] of 1979, Nautilus set out from Groton, Connecticut on her final voyage under the command of Richard A.Sony VAIO VPCCW1S1E/R Battery

Riddell. She reached Mare Island Naval Shipyard of Vallejo, California on 26 May 1979, her last day underway. She was decommissioned and stricken from the Naval Vessel Register on 3 March 1980. Sony VAIO VPCCW1S1E/W Battery

Noise

The hull and superstructure of Nautilus vibrated sufficiently that sonar became ineffective at more than 4 knots (7.4 km/h) speed.^[12] Also, noise generation is extremely undesirable in submarines as this makes the vessel vulnerable to detection. Lessons learned from this problem were applied to later nuclear submarines. Sony VAIO VPCCW21FX/B Battery

Presidential Unit Citation

For outstanding achievement in completing the first voyage in history across the top of the world, by cruising under the Arctic ice cap from the Bering Strait to the Greenland Sea.

"During the period 22 July 1958 to 5 August 1958, U.S.S. 
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NAUTILUS, the world's first atomic powered ship, added to her list of historic achievements by crossing the Arctic Ocean from the Bering Sea to the Greenland Sea, passing submerged beneath the geographic North Pole. This voyage opens the possibility of a new commercial seaway, a Northwest Passage, between the major oceans of the world. Sony VAIO VPCCW21FX/R Battery

Nuclear powered cargo submarines may, in the future, use this route to the advantage of world trade.

"The skill, professional competency and courage of the officers and crew of NAUTILUS were in keeping with the highest traditions of the Armed Forces of the United States and the pioneering spirit which has always characterized our country."^[13] Sony VAIO VPCCW21FX/W Battery

To commemorate the first submerged voyage under the North Pole, all members of the Nautilus crew who made the voyage are authorized to wear their Presidential Unit Citation ribbon with a special clasp in the form of a gold block letter N. (see image above).^[14]